Monkeypox virus infection – Evolution, molecular biology, epidemiology, clinical features and management aspects

Monkeypox virus (MPXV) infection has lately emerged as a new public health problem across 100 countries. Surging cases of MPXV infection in non-endemic countries prompted the World Health Organization to declare it a public health emergency in July 2022. The virological and clinical resemblance to eradicated smallpox disease has generated new scientific interest. This DNA orthopoxvirus primarily harbouring in squirrels, rats and non-human primates has led to infection in the human population. A recent surge of cases has been seen across 16 countries, with a clustering of cases in bisexual/homosexual men. The virus spreads through close contact with infected individuals with prodromal symptoms of fever and myalgia. A rash appears after 1–3 days of fever. There is presence of vesicular rash over the face, hands, feet and genital areas, and associated lymphadenopathy. Although no specific antiviral drugs directed against MPXV are available, tecovirimat developed against smallpox infection can be used and is effective. A synthetic analogue drug of cidofovir, i.e., brincidofovir has been evaluated for MPX patients in United Kingdom. A preventive strategy in close contacts may be offered through smallpox vaccines such as ACAM2000 and JYNNEOS. Epidemiological data from Africa suggest that smallpox vaccines provide 85% efficacy in preventing MPXV cases. Vaccinia immunoglobulin intravenous (VIGIV) has been used in immunocompromised patients with T-cell defects as prophylaxis where the use of vaccines is contraindicated. VIGIV can be used as a treatment modality for smallpox or non-variola infections like monkeypox in an outbreak, although the efficacy data are lacking.